source4/heimdal/base/heimqueue.h

   1 /*      $NetBSD: queue.h,v 1.38 2004/04/18 14:12:05 lukem Exp $ */
   2 /*      $Id$ */
   3
   4 /*
   5  * Copyright (c) 1991, 1993
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  *      @(#)queue.h     8.5 (Berkeley) 8/20/94
  33  */
  34
  35 #ifndef _HEIM_QUEUE_H_
  36 #define _HEIM_QUEUE_H_
  37
  38 /*
  39  * Tail queue definitions.
  40  */
  41 #define HEIM_TAILQ_HEAD(name, type)                                     \
  42 struct name {                                                           \
  43         struct type *tqh_first; /* first element */                     \
  44         struct type **tqh_last; /* addr of last next element */         \
  45 }
  46
  47 #define HEIM_TAILQ_HEAD_INITIALIZER(head)                               \
  48         { NULL, &(head).tqh_first }
  49 #define HEIM_TAILQ_ENTRY(type)                                          \
  50 struct {                                                                \
  51         struct type *tqe_next;  /* next element */                      \
  52         struct type **tqe_prev; /* address of previous next element */  \
  53 }
  54
  55 /*
  56  * Tail queue functions.
  57  */
  58 #if defined(_KERNEL) && defined(QUEUEDEBUG)
  59 #define QUEUEDEBUG_HEIM_TAILQ_INSERT_HEAD(head, elm, field)             \
  60         if ((head)->tqh_first &&                                        \
  61             (head)->tqh_first->field.tqe_prev != &(head)->tqh_first)    \
  62                 panic("HEIM_TAILQ_INSERT_HEAD %p %s:%d", (head), __FILE__, __LINE__);
  63 #define QUEUEDEBUG_HEIM_TAILQ_INSERT_TAIL(head, elm, field)             \
  64         if (*(head)->tqh_last != NULL)                                  \
  65                 panic("HEIM_TAILQ_INSERT_TAIL %p %s:%d", (head), __FILE__, __LINE__);
  66 #define QUEUEDEBUG_HEIM_TAILQ_OP(elm, field)                            \
  67         if ((elm)->field.tqe_next &&                                    \
  68             (elm)->field.tqe_next->field.tqe_prev !=                    \
  69             &(elm)->field.tqe_next)                                     \
  70                 panic("HEIM_TAILQ_* forw %p %s:%d", (elm), __FILE__, __LINE__);\
  71         if (*(elm)->field.tqe_prev != (elm))                            \
  72                 panic("HEIM_TAILQ_* back %p %s:%d", (elm), __FILE__, __LINE__);
  73 #define QUEUEDEBUG_HEIM_TAILQ_PREREMOVE(head, elm, field)               \
  74         if ((elm)->field.tqe_next == NULL &&                            \
  75             (head)->tqh_last != &(elm)->field.tqe_next)                 \
  76                 panic("HEIM_TAILQ_PREREMOVE head %p elm %p %s:%d",      \
  77                       (head), (elm), __FILE__, __LINE__);
  78 #define QUEUEDEBUG_HEIM_TAILQ_POSTREMOVE(elm, field)                    \
  79         (elm)->field.tqe_next = (void *)1L;                             \
  80         (elm)->field.tqe_prev = (void *)1L;
  81 #else
  82 #define QUEUEDEBUG_HEIM_TAILQ_INSERT_HEAD(head, elm, field)
  83 #define QUEUEDEBUG_HEIM_TAILQ_INSERT_TAIL(head, elm, field)
  84 #define QUEUEDEBUG_HEIM_TAILQ_OP(elm, field)
  85 #define QUEUEDEBUG_HEIM_TAILQ_PREREMOVE(head, elm, field)
  86 #define QUEUEDEBUG_HEIM_TAILQ_POSTREMOVE(elm, field)
  87 #endif
  88
  89 #define HEIM_TAILQ_INIT(head) do {                                      \
  90         (head)->tqh_first = NULL;                                       \
  91         (head)->tqh_last = &(head)->tqh_first;                          \
  92 } while (/*CONSTCOND*/0)
  93
  94 #define HEIM_TAILQ_INSERT_HEAD(head, elm, field) do {                   \
  95         QUEUEDEBUG_HEIM_TAILQ_INSERT_HEAD((head), (elm), field)         \
  96         if (((elm)->field.tqe_next = (head)->tqh_first) != NULL)        \
  97                 (head)->tqh_first->field.tqe_prev =                     \
  98                     &(elm)->field.tqe_next;                             \
  99         else                                                            \
 100                 (head)->tqh_last = &(elm)->field.tqe_next;              \
 101         (head)->tqh_first = (elm);                                      \
 102         (elm)->field.tqe_prev = &(head)->tqh_first;                     \
 103 } while (/*CONSTCOND*/0)
 104
 105 #define HEIM_TAILQ_INSERT_TAIL(head, elm, field) do {                   \
 106         QUEUEDEBUG_HEIM_TAILQ_INSERT_TAIL((head), (elm), field)         \
 107         (elm)->field.tqe_next = NULL;                                   \
 108         (elm)->field.tqe_prev = (head)->tqh_last;                       \
 109         *(head)->tqh_last = (elm);                                      \
 110         (head)->tqh_last = &(elm)->field.tqe_next;                      \
 111 } while (/*CONSTCOND*/0)
 112
 113 #define HEIM_TAILQ_INSERT_AFTER(head, listelm, elm, field) do {         \
 114         QUEUEDEBUG_HEIM_TAILQ_OP((listelm), field)                      \
 115         if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
 116                 (elm)->field.tqe_next->field.tqe_prev =                 \
 117                     &(elm)->field.tqe_next;                             \
 118         else                                                            \
 119                 (head)->tqh_last = &(elm)->field.tqe_next;              \
 120         (listelm)->field.tqe_next = (elm);                              \
 121         (elm)->field.tqe_prev = &(listelm)->field.tqe_next;             \
 122 } while (/*CONSTCOND*/0)
 123
 124 #define HEIM_TAILQ_INSERT_BEFORE(listelm, elm, field) do {              \
 125         QUEUEDEBUG_HEIM_TAILQ_OP((listelm), field)                      \
 126         (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
 127         (elm)->field.tqe_next = (listelm);                              \
 128         *(listelm)->field.tqe_prev = (elm);                             \
 129         (listelm)->field.tqe_prev = &(elm)->field.tqe_next;             \
 130 } while (/*CONSTCOND*/0)
 131
 132 #define HEIM_TAILQ_REMOVE(head, elm, field) do {                        \
 133         QUEUEDEBUG_HEIM_TAILQ_PREREMOVE((head), (elm), field)           \
 134         QUEUEDEBUG_HEIM_TAILQ_OP((elm), field)                          \
 135         if (((elm)->field.tqe_next) != NULL)                            \
 136                 (elm)->field.tqe_next->field.tqe_prev =                 \
 137                     (elm)->field.tqe_prev;                              \
 138         else                                                            \
 139                 (head)->tqh_last = (elm)->field.tqe_prev;               \
 140         *(elm)->field.tqe_prev = (elm)->field.tqe_next;                 \
 141         QUEUEDEBUG_HEIM_TAILQ_POSTREMOVE((elm), field);                 \
 142 } while (/*CONSTCOND*/0)
 143
 144 #define HEIM_TAILQ_FOREACH(var, head, field)                            \
 145         for ((var) = ((head)->tqh_first);                               \
 146                 (var);                                                  \
 147                 (var) = ((var)->field.tqe_next))
 148
 149 #define HEIM_TAILQ_FOREACH_REVERSE(var, head, headname, field)          \
 150         for ((var) = (*(((struct headname *)((head)->tqh_last))->tqh_last)); \
 151                 (var);                                                  \
 152                 (var) = (*(((struct headname *)((var)->field.tqe_prev))->tqh_last)))
 153
 154 /*
 155  * Tail queue access methods.
 156  */
 157 #define HEIM_TAILQ_EMPTY(head)          ((head)->tqh_first == NULL)
 158 #define HEIM_TAILQ_FIRST(head)          ((head)->tqh_first)
 159 #define HEIM_TAILQ_NEXT(elm, field)             ((elm)->field.tqe_next)
 160
 161 #define HEIM_TAILQ_LAST(head, headname) \
 162         (*(((struct headname *)((head)->tqh_last))->tqh_last))
 163 #define HEIM_TAILQ_PREV(elm, headname, field) \
 164         (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
 165
 166
 167 #endif  /* !_HEIM_QUEUE_H_ */